A technology has been disclosed in which releasing locking of an opening/closing body, and an opening operation of the opening/closing body are automatically performed by a driver (user) having an electronic key performing a kicking motion in a vicinity of the opening/closing body when the driver is about to open or close the opening/closing body such as a trunk, a rear gate, a hinged door, and a sliding door of a vehicle (for example, PATENT LITERATURE 1 and PATENT LITERATURE 2).
According to the device described in PATENT LITERATURE 1, electrostatic sensors for detecting approach of the user are provided at two different places around the trunk. Then, after an upper sensor detects approach of a portion near the user's knee, when a lower sensor detects approach of a distal portion from the user's ankle, it is determined that the kicking motion has been performed. Then, the rear gate opens.
In the device described in PATENT LITERATURE 2, one upper electrostatic sensor and a plurality of lower electrostatic sensors are provided. Then, when two or more of the plurality of lower sensors detect the approach at the same time, the rear gate is controlled not to open. In this way, an erroneous operation is prevented.